David's Astronomy Pages
Notes - Session 947 (2022-01-01)

 
Bullet Session Aims & Highlights
 - Observing Result
 - Night Summary Plot
 - Session Event Log
 
Bullet Operational Issues
  - Critical Issues (0),  Major Issues (0),  Minor Issues (5),  Small Defects (2),  Continuous Improvement (1)
 
Bullet Images from 2022-01-01 >>         [ Local Files >> ]
2022-01-02
Bullet Review - LX200 Temperatures (":fT#")
Bullet SBIG Camera Bias Level (Sky Brightness Issue & Fix)

Session Aims & Highlights (2022-01-01)

Main aims

  1. Centering. Test out JogUsingPulseGuide () routine for jogs in range 2 to 5 arc min.
  2. Guiding Performance. Test out guiding performance using new
  3. Targets.  Acquire images of a selection of variable stars, nearby stars, comets & deep sky targets as allowed by time & conditions.

Equipment & Software

Highlights

Notes:

  Summary Plots & Logs

Observing Plan
Image
  
Observing Result
Image
   
  
Dome & Scope Slewing Performance
Image
  
Slew/Centering Performance
Image
  
Guiding Performance
Reasons for poor Dec guiding :
Black points (39, 40, 41)   - Cloud
Purple point (4)   - Ineffective Dec Guiding.  Also Cloud affecting RA Guiding
Red points (2)   - Anomalous Dec point (8" error) caused overreaction Dec Guiding
which drove telescope to wrong side of zero line (Frame 2). Although error corrected by Frame 3
the impact on overall Dec GuideStats was significant.
Red point (7)   - Ineffective Dec Guiding (near zenith, can't drive south).
Red points (34)   - Anomalous Dec point (7" error) caused overreaction Dec Guiding
which drove telescope to wrong side of zero line by 7" (Frame 3). Although error corrected by Frame 4
the impact on overall Dec GuideStats was significant.
Orange points (33)   - Anomalous Dec point (4.5" error) caused overreaction Dec Guiding
which drove telescope to wrong side of zero line by 3" (Frame 2). Although error corrected by Frame 4
the overall Dec GuideStats had been effected.
Orange points (23)   -  Scope on wrong side of zero line or inappropriate Principal DecGuideMode (target very close to Meridian
Green points (18)   - Dec Guiding ok, but significant Ra error > 8" that was difficult to correct (purple RA point)
Image
Image
  
Sky Conditions (Locate Frames)
Sky Brightness measurements are invalid due to a SBIG camera bias level issue (eventually fixed 2022-01-02)
Image
 
Night Sky Summary Plot
Top axis: Sky Brightness at Zenith (in ADU/s)
Lefthand axis: Local Time (hh LT). Righthand axis: Sun Altitude (degs)

Image   
  
Actual Weather vs Pre-Session Weather Forecast
Image
Image   
  
Session Event Log
Time     Event Detail
16:32:18 Session Monitoring AutoStart monitoring for Live Session opportunity between 16:45 & 06:27
16:32:20   AutoStart Waiting AutoStart waiting till earliest start time at 16:45
16:45:36   AutoStart Delayed Session delayed due to too few stars
17:00:43 Session AutoStarting Session autostarting (17:00)
17:01:11 Session Created Live Session Created (2022-01-01 S00947, ImageSaveNum: 947001)
17:01:14   Scope Switched On Telescope Power has been switched on via UPB Powerbox.
17:02:55   Services Started Observatory Services started
17:03:02 Observatory (Auto) Observatory placed in Fully-Automated Mode
17:03:05 Session Pending Session pending (2022-01-01)
17:03:07 Session Initiating Session initiating (2022-01-01)
17:03:09   Plan Requested Observing Plan requested from AstroPlan (1.29.2)
17:03:52   Plan Loaded Observing Plan loaded to queue (, Plan ID: 701)
17:04:13   Camera1 Connected SBIG Camera Connected (set point -15°C)
17:04:20   Telescope Connected Telescope Connected (TheSky6)
17:04:44 Session Equilibration Session ready for dome & camera equilibration
17:05:29   Dome Opened Dome opened (opening time 45s)
17:06:09 Session Running Session running
17:06:11   Queue Started Observing Queue started (43 targets selected)
17:06:14     Target Started (NrZen) Target started (Focus Field 0, HIP 106)
17:07:54       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
17:11:08       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide)
17:13:14       Focusing Failed Foc1 focusing failed (failed QC check - Ambiguous)
17:13:16       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap)
17:15:26       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide)
17:17:13       Focusing Completed Foc2 AutoFocus Completed (Profile No 2)
17:17:31     Target Completed Target completed (Focus Field 0, HIP 106)
17:18:12     Target Started (1/43) Target started (1/43, Nova Cas 2021)
17:21:32       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
17:24:33       Focusing Completed Foc1 AutoFocus Completed (Profile No 3, wide)
17:26:31       Focusing Completed Foc1 AutoFocus Completed (Profile No 3)
17:33:29     Target Completed Target completed (1/43, Nova Cas 2021)
17:33:33     Target Started (2/43) Target started (2/43, AT2021afpi)
17:37:25       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
17:39:25       Focusing Completed Foc1 AutoFocus Completed (Profile No 4)
17:45:50     Target Completed Target completed (2/43, AT2021afpi)
17:45:54     Target Started (3/43) Target started (3/43, UGC 2528 w/SN2020adnx)
17:48:30       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
17:50:31       Focusing Completed Foc1 AutoFocus Completed (Profile No 5)
18:07:19     Target Completed Target completed (3/43, UGC 2528 w/SN2020adnx)
18:07:23     Target Started (4/43) Target started (4/43, AT2021kkh)
18:07:32     Target Failed Target failed due to slew error (4/43, AT2021kkh)
18:27:01     Target Started (5/43) Target started (5/43, C/2019 L3 (ATLAS))
18:29:51       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:31:52       Focusing Completed Foc1 AutoFocus Completed (Profile No 6)
18:42:11     Target Completed Target completed (5/43, C/2019 L3 (ATLAS))
18:42:15     Target Started (6/43) Target started (6/43, UGC 4002 w/SN2021wvy)
18:45:00       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
18:46:21 Critical Wind Alert Critical Wind Alert (Obs.Manager will close the Dome)
18:46:23   HardSuspend Called Hard Suspend is called due to Critical Conditions (wind)
18:46:30       Focusing Aborted Foc1 Focusing Aborted
18:46:32     Target Aborted (6/43) Target aborted (6/43, UGC 4002 w/SN2021wvy) due to wind
18:46:34   Queue Paused Queue paused for Session Suspension
18:46:36 Session Suspended Session suspended
18:47:21   Dome Closed Dome closed (closing time 49s)
19:00:04     Target Cancelled Target cancelled (6/43, UGC 4002 w/SN2021wvy) due to wind
19:21:56     Target Cancelled Target cancelled (7/43, UGC 4671 w/SN2021afsj) due to wind
19:23:41 Session Resuming Session resuming
19:24:26   Dome Opened Dome opened (opening time 45s)
19:24:28 Session Running Session running
19:24:30   Queue Resumed Observing Queue resumed
19:25:00     Target Started (8/43) Target started (8/43, Nova Per 2020)
19:28:12       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-S)
19:36:40     Target Completed Target completed (8/43, Nova Per 2020)
19:39:52     Target Started (9/43) Target started (9/43, NGC 1569 w/AT2021aczn)
19:42:50       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
19:44:56       Focusing Completed Foc1 AutoFocus Completed (Profile No 8)
20:03:00     Target Completed Target completed (9/43, NGC 1569 w/AT2021aczn)
20:03:04     Target Started (10/43) Target started (10/43, 67P/Churyumov-Gerasimenko)
20:06:21       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
20:08:42       Focusing Completed Foc1 AutoFocus Completed (Profile No 9)
20:22:40     Target Completed Target completed (10/43, 67P/Churyumov-Gerasimenko)
20:22:42   Queue Aborted Job Queue aborted
20:22:52   Services Stopped Observatory Services stopped
20:22:56 Program Closed Program closed by User
20:23:37 Session Resumed Live Session Resumed (2022-01-01 S00947, ImageSaveNum: 947071)
20:23:48   Obs.Manager Started Obs.Manager started
20:23:50   Obs.Overseer Started Obs.Overseer started
20:23:54   Services Started Observatory Services started
20:24:21   Camera1 Connected SBIG Camera Connected (set point -15°C)
20:24:33 Session Monitoring AutoStart monitoring for Live Session opportunity between 20:24 & 06:27
20:24:35 Observatory (AutoStart) Observatory placed in Auto-Start Mode
20:24:37   AutoStart Delayed Session delayed due to threat of rain
20:24:58 Observatory (Manual) Observatory placed in Manual Mode
20:25:46   Services Started Observatory Services started
20:25:59   Telescope Connected Telescope Connected (TheSky6)
20:26:23 Observatory (Auto) Observatory placed in Fully-Automated Mode
20:26:26 Session Pending Session pending (2022-01-01)
20:26:28 Session Initiating Session initiating (2022-01-01)
20:26:33   Plan Loaded Observing Plan loaded to queue (, Plan ID: 701)
20:26:45   Camera1 Connected SBIG Camera Connected (set point -15°C)
20:26:50   Telescope Connected Telescope Connected (TheSky6)
20:27:11 Session Equilibration Session ready for dome & camera equilibration
20:27:13 Session Running Session running
20:27:15   Queue Started Observing Queue started (33 targets selected)
20:27:20     Target Started (11/43) Target started (11/43, AT2021acba)
20:46:17     Target Completed Target completed (11/43, AT2021acba)
20:46:21     Target Started (12/43) Target started (12/43, PKS0735+17 w/AT2021agfn)
20:49:22       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
20:51:35       Focusing Completed Foc1 AutoFocus Completed (Profile No 15)
21:08:45     Target Completed Target completed (12/43, PKS0735+17 w/AT2021agfn)
21:08:50     Target Started (13/43) Target started (13/43, UGCA 240)
21:12:33       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:14:36       Focusing Completed Foc1 AutoFocus Completed (Profile No 16)
21:31:58     Target Completed Target completed (13/43, UGCA 240)
21:32:02     Target Started (14/43) Target started (14/43, GCVS SS Cyg)
21:35:33       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:37:46       Focusing Completed Foc1 AutoFocus Completed (Profile No 17)
21:42:58     Target Completed Target completed (14/43, GCVS SS Cyg)
21:43:03     Target Started (15/43) Target started (15/43, GCVS HH And)
21:46:11       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:48:25       Focusing Completed Foc1 AutoFocus Completed (Profile No 18)
21:52:00     Target Completed Target completed (15/43, GCVS HH And)
21:52:04     Target Started (16/43) Target started (16/43, GCVS RR Tau)
21:55:26       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
21:57:43       Focusing Completed Foc1 AutoFocus Completed (Profile No 19)
22:05:15     Target Completed Target completed (16/43, GCVS RR Tau)
22:05:17   Queue Aborted Job Queue aborted
22:05:27   Services Stopped Observatory Services stopped
22:05:31 Program Closed Program closed by User
22:06:07 Session Resumed Live Session Resumed (2022-01-01 S00947, ImageSaveNum: 947124)
22:07:45   Obs.Manager Started Obs.Manager started
22:07:47   Obs.Overseer Started Obs.Overseer started
22:07:51   Services Started Observatory Services started
22:08:09   Telescope Connected Telescope Connected (TheSky6)
22:08:30 Observatory (Auto) Observatory placed in Fully-Automated Mode
22:08:32 Session Pending Session pending (2022-01-01)
22:08:35 Session Initiating Session initiating (2022-01-01)
22:08:40   Plan Loaded Observing Plan loaded to queue (, Plan ID: 701)
22:08:52   Camera1 Connected SBIG Camera Connected (set point -15°C)
22:08:57   Telescope Connected Telescope Connected (TheSky6)
22:09:16 Session Equilibration Session ready for dome & camera equilibration
22:09:18 Session Running Session running
22:09:21   Queue Started Observing Queue started (27 targets selected)
22:09:25     Target Started (17/43) Target started (17/43, AT2021bnz)
22:25:55     Target Completed Target partially completed (17/43, AT2021bnz)
22:25:59     Target Started (18/43) Target started (18/43, UGC 5829 w/LBV2021blu)
22:28:54       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:31:06       Focusing Completed Foc1 AutoFocus Completed (Profile No 20)
22:47:48     Target Completed Target completed (18/43, UGC 5829 w/LBV2021blu)
22:47:52     Target Started (19/43) Target started (19/43, NGC 7446 w/SN2021agdd)
22:52:26       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
22:54:34       Focusing Completed Foc1 AutoFocus Completed (Profile No 21)
23:08:43     Target Completed Target partially completed (19/43, NGC 7446 w/SN2021agdd)
23:08:47     Target Started (20/43) Target started (20/43, GCVS BL Lac)
23:12:38       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:14:51       Focusing Completed Foc1 AutoFocus Completed (Profile No 22)
23:19:12     Target Completed Target completed (20/43, GCVS BL Lac)
23:19:16     Target Started (21/43) Target started (21/43, UGC 3855 w/SN2021agco)
23:23:05       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:25:05       Focusing Completed Foc1 AutoFocus Completed (Profile No 23)
23:41:30     Target Completed Target completed (21/43, UGC 3855 w/SN2021agco)
23:41:34     Target Started (22/43) Target started (22/43, AT2021xbh)
23:44:57       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
23:47:09       Focusing Completed Foc1 AutoFocus Completed (Profile No 24)
00:03:13     Target Completed Target completed (22/43, AT2021xbh)
00:03:17     Target Started (23/43) Target started (23/43, AT2021hfr)
00:06:27       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:08:28       Focusing Completed Foc1 AutoFocus Completed (Profile No 25)
00:25:09     Target Completed Target completed (23/43, AT2021hfr)
00:25:13     Target Started (24/43) Target started (24/43, UGC 1098 w/AT2021ahep)
00:28:38       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:30:37       Focusing Completed Foc1 AutoFocus Completed (Profile No 26)
00:47:30     Target Completed Target completed (24/43, UGC 1098 w/AT2021ahep)
00:47:34     Target Started (25/43) Target started (25/43, AT2021agjs)
00:51:03       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
00:52:52       Focusing Completed Foc1 AutoFocus Completed (Profile No 27)
01:10:39     Target Completed Target completed (25/43, AT2021agjs)
01:10:44     Target Started (26/43) Target started (26/43, NGC 2761 w/SN2021aggu)
01:13:40       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:16:29       Focusing Completed Foc1 AutoFocus Completed (Profile No 28)
01:33:11     Target Completed Target completed (26/43, NGC 2761 w/SN2021aggu)
01:33:15     Target Started (27/43) Target started (27/43, GCVS SY Cnc)
01:36:06       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:38:42       Focusing Completed Foc1 AutoFocus Completed (Profile No 29)
01:42:26     Target Completed Target completed (27/43, GCVS SY Cnc)
01:42:30     Target Started (28/43) Target started (28/43, UGC 1971 w/SN2021afkk)
01:46:21       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
01:48:21       Focusing Completed Foc1 AutoFocus Completed (Profile No 30)
02:02:29     Target Completed Target partially completed (28/43, UGC 1971 w/SN2021afkk)
02:02:33     Target Started (29/43) Target started (29/43, Scholz's Star)
02:05:50       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:07:50       Focusing Completed Foc1 AutoFocus Completed (Profile No 31)
02:24:42     Target Completed Target completed (29/43, Scholz's Star)
02:24:46     Target Started (30/43) Target started (30/43, Hickson 39)
02:27:51       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:30:03       Focusing Completed Foc1 AutoFocus Completed (Profile No 32)
02:46:06     Target Completed Target completed (30/43, Hickson 39)
02:46:10     Target Started (31/43) Target started (31/43, UGCA 173)
02:49:19       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
02:51:54       Focusing Completed Foc1 AutoFocus Completed (Profile No 33)
03:07:58     Target Completed Target completed (31/43, UGCA 173)
03:08:02     Target Started (32/43) Target started (32/43, AT2021agmc)
03:10:51       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
03:13:09       Focusing Completed Foc1 AutoFocus Completed (Profile No 34)
03:29:16     Target Completed Target completed (32/43, AT2021agmc)
03:29:20     Target Started (33/43) Target started (33/43, NGC 3310 w/SN2021gmj)
03:32:14       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
03:34:27       Focusing Completed Foc1 AutoFocus Completed (Profile No 35)
03:50:32     Target Completed Target completed (33/43, NGC 3310 w/SN2021gmj)
03:50:36     Target Started (34/43) Target started (34/43, UGCA 276)
03:53:27       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
03:55:44       Focusing Completed Foc1 AutoFocus Completed (Profile No 36)
04:12:45     Target Completed Target completed (34/43, UGCA 276)
04:12:50     Target Started (35/43) Target started (35/43, UGC 8426 w/AT2021knq)
04:20:42       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-S)
04:37:12     Target Completed Target completed (35/43, UGC 8426 w/AT2021knq)
04:37:16     Target Started (36/43) Target started (36/43, NGC 4165 w/SN2021gno)
04:40:09       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
04:42:19       Focusing Completed Foc1 AutoFocus Completed (Profile No 37)
04:59:13     Target Completed Target completed (36/43, NGC 4165 w/SN2021gno)
04:59:17     Target Started (37/43) Target started (37/43, IC 3322A w/SN2021hiz)
05:02:10       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-S)
05:18:19     Target Completed Target completed (37/43, IC 3322A w/SN2021hiz)
05:18:23     Target Started (38/43) Target started (38/43, MCG +6-30-84 w/SN2021K)
05:20:47       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
05:22:53       Focusing Completed Foc1 AutoFocus Completed (Profile No 38)
05:39:38     Target Completed Target completed (38/43, MCG +6-30-84 w/SN2021K)
05:40:09     Target Started (39/43) Target started (39/43, UGC 8975 w/AT2021adpe)
05:42:45       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
05:45:03       Focusing Completed Foc1 AutoFocus Completed (Profile No 39)
06:01:47     Target Completed Target completed (39/43, UGC 8975 w/AT2021adpe)
06:02:01     Target Started (40/43) Target started (40/43, GCVS R CrB)
06:04:52       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S)
06:06:33       Focusing Completed Foc1 AutoFocus Completed (Profile No 40)
06:10:21     Target Completed Target completed (40/43, GCVS R CrB)
06:10:42     Target Started (41/43) Target started (41/43, AT2021agpw (CV))
06:15:29       Focusing Skipped Foc1 focusing skipped - star is lost (TCF-S)
06:21:26     Target Completed Target completed (41/43, AT2021agpw (CV))
06:22:34     Target Started (42/43) Target started (42/43, IC 4593)
06:26:57       Focusing Skipped Foc1 focusing skipped - unable to find a star (TCF-S)
06:31:42   SoftSuspend Called Soft Suspend is called due to Deteriorating Conditions (too few stars)
06:53:11     Target Completed Target completed (42/43, IC 4593)
06:53:13   Queue Paused Queue paused for Session Suspension
06:53:14 Session Suspended Session suspended
06:54:04   Dome Closed Dome closed (closing time 50s)
06:55:50 Session Resuming Session resuming
06:56:35   Dome Opened Dome opened (opening time 45s)
06:56:37 Session Running Session running
06:56:39   Queue Resumed Observing Queue resumed
06:56:41     Target Started (43/43) Target started (43/43, C/2017 K2 (PANSTARRS))
06:59:59       Focusing Skipped Foc1 focusing skipped - unable to find a star (TCF-S)
07:08:16     Target Completed Target completed (43/43, C/2017 K2 (PANSTARRS))
07:08:19   Queue Completed Job Queue completed
07:08:21 Session Closing Session closing
07:09:16   Dome Closed Dome closed (closing time 50s)
07:09:33   Dome Parked Dome parked (parking time 10s), Az: 90.0 deg
07:11:04   Telescope Parked Telescope parked (parking time 86s)
07:11:24   Telescope State Scope parked Turn scope off. (Handbox)
07:11:46   Telescope Switched Off Telescope Power has been switched off via UPB Switch.
07:12:38   Services Stopped Night Services stopped
07:12:40 Session Housekeeping Housekeeping Started (Cleanup FITS, Create Fits Summary, Transfer Files)
07:13:11 Session Finished Session Finished
 
Session Alerts
Time     Alert Detail
19:55:25 Dome Dome has been stationary for more than 15 mins
20:03:15 Dome Dome Movements have begun again (outage 22.9 mins)

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Operational Issues (2022-01-01, S947)

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Critical Issues

Major Issues

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2022-01-02


Review - LX200GPS Temperature (":fT#")

After discovering that a CommandString(":fT#", True) command could be used to access a temperature reading from the observatory's LX200GPS Telescope monitoring routines were modified to read the temperature every 20s and plot it as a line on the Focus Temperature charts alongside other temperature readings from the observatory. It was qucikly discovered that the LX200GPS Temperature showed a very poor correlation with other that from other sensors.  Applying a trim (correction) setting didn't help nor did sending a command to ensure that scope's GPS is turned off (as this uses circuitary that is understood to warm the readings returned by the LX200GPS Temperature.

The following plot from the S947 sessions displays the LX200GPS Temperatures returned by CommandString(":fT#", True) as a magenta line.  This is plotted in degC after conversion from raw (degF) values from the scope.   The plot provides further proof that the LX200GPS temperatures are unreliable and of no pratical use for observatory monitoring.

Image

In the following S948 session the temperature returned by :fT#  started out returning temperatures of 23.8 to 18.8°C, far higher than the observatory ambient temperature of  1°C, and then at  18:24  the temperature returned from the LX200 telescope suddenly dropped from +18.8°C to -10.4°C in 20s, after which it gradually fell to an eventual low of -16.4°C.   This is an impossibly low number unless the scope has a built in freezer !

Conclusion
Although only recently introduced,  enough data has now been collected to show that the temperatures returned by the observatory's LX200GPS telescope is anomalous & unreliable for most of the time (being either too hot or too cold) and with trends that simply don't reflect the trends seen by other tenperature sesnors used inside & outside the observatory. Reading the temperature value too frequently can also cause the LX200 Telescope/Driver processing to slow down to the point that major problems are seen during slewing, centering and guiding.  

Action
Withdraw Scope.Temperature from AstroMain. 
- remove Scope.Temparture property (stop using :fT# command)
- remove ScopeTemperature from the Focus Temp Chart & from the ObsPic Chart
- remove Scope.Temperature from the Observatory Tab & Virtual Model.

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SBIG Camera Bias Level (Sky Brightness Issue & Fix)

Following replacement of the Observatory Computer with a new one on 2021-12-10 it has been noticed that session plots showing the Sky Brightness as determined by background ADU rates per second appeared to show much brighter sky that expected.  These are determinated from Locate Frames taken with C Filter.   Initial sessions after changing to the new observatory computer corresponded with a near full / full moon, and the issue was initially dismissed. 
A vignetting artefact seen in recent (reduced) images was noticed but there had been no change to the imaging setup to explain this.

Subsequent sessions in which the moon lay below the horizon showed that the initial was real. 
See following Sky Brightness plot from the recent S947 session (2022-01-01).

Image

With the possibility that the problem related to stray IR light from the Observatory WebCam coding was changed to turn off the camera/IR lights during Locate Frames (in addition to main image frames) but this didn't resolve the issue.  

Further Analysis
Tests taking dark and bias frames showed that they were giving much higher average/peak values than dark/bias frames taken before changing to the new computer.  Normal bias reading (from 3x3 binned frames) is around 160-170 ADU,  but the new frames returned values around 1000 ADU.

It is speculated that a vignetting effect seen in recent images that have been reduced using older Flat frames is an artefact of this bias level problem.

Fix
It was hypothesized that this related in some way to the drivers installed for the SBIG camera when setting up the new Observatory Computer.
Investigating it was noticed that on the driver's 'Configure Driver' tab there was a 'Auto Bias Level Correction' option which was unchecked.  

This option was checked, applied (using Ok) and the drivers reinstalled.   Post-modification checks showed that the camera was again producing Bias frames and short dark exposure frames with the expected normal low values of around 165 ADU

Image

Confirmation
Sky Brightness plot from the following S948 session (2022-01-03) shows that Sky Brightness values derived from CCD Images have returned to their expected values.

Image

Update 2022-08-10
The same issue was noticed 2022-08-10 in images taken in session S1024 (2022-08-04) which followed reinstallation of Windows 10 / reinstallation of SBIG Camera on 2022-06-21.  Problem wasn't noticed initially as the bright background was put down to bright twilight skies in June/July, but by August it was evident that something was wrong.

Again the same solution to SBIG Driver Configuration appears to have fixed this later problem.

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